基于BDNF/PI3K/AKT信号通路探讨四君子汤对脾气虚证大鼠学习记忆功能的影响

Effect of Sijunzi Decoction(四君子汤)on Learning and Memory Function of Rats with Piqixu(脾气虚)Syndrome Based on BDNF/PI3K/AKT Signaling Pathway

目的:通过检测脾气虚证大鼠海马组织中BDNF/PI3K/AKT信号通路蛋白表达水平,探讨四君子汤对脾气虚大鼠学习记忆功能的影响。方法:将72只SPF级Wistar大鼠随机分为正常对照组和造模组,造模组大鼠采用综合造模法(苦寒泻下法+饮食失常+劳倦过度)复制脾气虚证模型,将成模大鼠按照随机数字表法分为模型对照组、阳性对照补中益气汤1.1 g/kg组和四君子汤6、12、24 g/kg组,每组12只,给药期间除正常对照组外,其余各组均继续造模,持续干预21 d后,采用Morris水迷宫测定大鼠学习记忆能力,剖取大鼠脑(海马)组织,采用HE染色法观察大鼠海马组织病理形态学改变;采用蛋白免疫印迹法检测大鼠海马组织中BDNF/PI3K/AKT蛋白表达。结果:与正常对照组比较,模型对照组大鼠出现少食、倦卧、便溏等脾气虚症状,逃避潜伏期明显延长、穿越平台次数明显减少,有效区内停留时间明显缩短(P<0.05),海马组织CA1区神经元数目减少、排列紊乱,海马组织中BDNF、PI3K、AKT蛋白表达均显著下调(P<0.05);与模型对照组比较,各药物组大鼠体质量增加、活动增加、便质成形,逃避潜伏期明显缩短、穿越平台次数明显增加,有效区内停留时间明显增加(P<0.05),海马组织病理形态不同程度改善,海马组织中BDNF、PI3K、AKT蛋白表达明显上调(P<0.05)。结论:四君子汤显著改善脾气虚证大鼠学习记忆能力以及海马组织的病理形态,其机制可能与四君子汤上调海马组织中BDNF/PI3K/AKT信号通路有关。

Objective:To investigate the effect of Sijunzi Decoction(四君子汤)on learning and memory function of rats with Piqixu(脾气虚)syndrome by determining the protein expression level of brain-derived neurotrophic factor/phosphoinositide 3 kinase/protein kinase B(BDNF/PI3 K/AKT)signaling pathway in the hippocampus.Methods:Seventy-two SPF Wistar rats were randomly divided into a normal control group and a model group.Rats in the model group were induced the model of Piqixu syndrome by comprehensive modeling method(Kuhanxiexia(苦寒泻下)+eating disorder+exhausting).After modeling,rats were randomly divided into model group,positive control group(1.1 g/kg Buzhongyiqi Decoction),and Sijunzi Decoction groups(6,12,and 24 g/kg),with 12 rats in each group.During the administration,groups continued to induce the model except for the normal control group.After intervention for 21 d,the learning and memory abilities of rats were measured by Morris water maze test.The rats were sacrificed to collect the hippocampus tissue,and hematoxylin-eosin(HE)staining was used to observe the pathological changes.The protein expressions of BDNF/PI3 K/AKT were determined by Western blot.Results:Compared with the rats in the normal control group,those in the model group showed the Piqixu syndrome such as diet reduction,tiredness,and feces rarefaction.In the model group,the escape latency was prolonged,the times of crossing the platform were reduced,and the staying time in the coverage area was shortened(P<0.05).The number of neurons in CA1 area of hippocampus decreased with disorganized order,and the protein expressions of BDNF,PI3 K,and AKT in the hippocampus of rats in the model group were down-regulated(P<0.05).As compared with the model group,the body weight and activities of rats in the administration groups were increased,and the feces were formed.The escape latency was shortened,the times of crossing the platform were increased,and the staying time in the coverage area was prolonged(P<0.05).The pathological morphology of hippocampus was improved to varying degree,and the protein expressions of BDNF,PI3 K,and AKT in the hippocampus of rats in the administration groups were up-regulated(P<0.05).Conclusion:Sijunzi Decoction significantly improves the learning and memory ability and pathological morphology of hippocampus in the rats with Piqixu syndrome.The mechanism may be related to the up-regulation of BDNF/PI3 K/AKT signaling pathway in the hippocampus tissue.